Adapter system for component assembly circuit boards, for use in a test device

ABSTRACT

The invention relates to a test device for component assembly circuit boards (31), in which this test device includes a plurality of test channels which are contact-connected with respective test points (32) of the board (31) by means of spring contact pins (2, 3), whereby in accordance with the invention for the contacting of the spring contact pits with the terminals of the test channels (29) there is provided a raster plate (21) which has contact surfaces (22) on the side to be contacted with the spring contact pins, of which contact surfaces in each case n contact surfaces are electrically parallel-connected with .one another and connected with a respective test channel, whereby the test surfaces (No. 1, No. 2, . . . , No. 21, No. 41, . . . ) of the test channels (a 1 , a 2 , . . . b 1 , . . . c 1 , . . .) are positioned on this outer surface of the raster plate distributed mixed with one another. 
     (FIG. 1)

BACKGROUND OF THE INVENTION

The present invention relates to an adapter system for componentassembly circuit boards, such as are employed in great number and in themost various designs in electronic apparatuses of the most varied size.Such circuit boards have individual electronic components mounted onthem.

On such an component assembly circuit board there are a plurality ofcomponents, component assemblies and the like, and numerous contact andsolder points are present, for which the possibility cannot be excludedthat a component, a solder point or the like could be defective. As aresult of such a defect, the complete component assembly board is forthe most part not useable and would not be tolerable if built into anelectronic apparatus, or would lead to complaints from the customer. Itis thus provided to test the component assembly circuit boards forcomplete freedom from faults, each individually, in accordance with atest program to be determined. Thereby, inter alia, the large number ofcontact points are to be tested with a view to determining whether theconductor paths, components and assemblies present on the board betweenthem have the required electronic properties. Clearly, this can beeconomically effected only by means of an automatically functioning testdevice, which tests at predetermined test points of the board theconductor path connections and the elements with which this componentassembly circuit board is mounted. For such a testing which runsautomatically, checking/test devices have been developed and areavailable which e.g. have in one plane a large number of contacts, e.g.spring contact tips. These contact tips are the respective externalterminals of the test channels of the checking/test device, whereby thefunctions of the individual test channels are set in accordance with astandard. When the test points of a component or of a component assemblyare connected each with such a contact tip, i.e. with a test channel ofthe test device, the connected element of the component assembly circuitboard can be checked with regard to its freedom from faults with thetest device.

There are known, e.g. from DE-A-4,226,069, standardized test deviceswith in each case a specific adapter part with which selected electricalconnections between respective test points of an component assemblycircuit board and respective contact tips of the test device areestablished. For this purpose, the plane of these contact tips and thecomponent assembly circuit board are arranged parallel to one anotherand one above another with a spacing, and contact elements are locatedin the space between the board and the test device which contactelements establish these connections in a selected manner for the caseconcerned. For this purpose it is usual to provide respective pairs ofcontact pins connected with one another by an electrical wire, of whichthe one pin contacts the selected test point and the other pin contactsthe respective associated selected contact tip of the test device.

With such known arrangements it is disadvantageous that individual, insome cases long, wire connections between the pins of a respective pairare to be provided, which give rise to high production costs and whichmay have undesirable effects in relation to high frequencies. Also, themanipulation therewith and the placement of the contact pin pairs isinconvenient and time consuming. Further, with this technique, problemscan appear particularly in the case of circuit boards having higherpacking density, because the available space is not always sufficientfor the two pins respectively required per contact connection.

From EP-0233992 A1 there has been known for almost a decade a furthertest device having an adapter for contacting matching to a respectivecomponent assembly circuit board, and this device is in use. The adapterhas first spring contact pins, fastened in a first plate, which pinscorrespond to the required contacting of test points of the circuitboard, are directed towards the board and are positioned distributedover the plate with regard to the area thereof. Second contact pins ofconstant length are fastened in this plate, directed towards the testdevice, which second contact pins are each positioned associated with arespective one of the first spring contact pins, neighbouring that firstspring contact pin. These respective pairs of contact pins areelectrically connected with one another by wires. This known adapteralso includes a second plate with the funnel-like holes of which,directed towards the second contact pins, the bendable contact ends ofthe second contact pins are so directed, upon pushing of the plate ontothe ends of these contact pins, that the contacting ends meet theselected spring contact tips of the test device. With this known adapterthere are always provided two pins of a pin pair for a respectiveconnection between the contact tip of the test device and the test pointof the board. For a respective connection there is thus needed space fortwo pins alongside one another. In the region of the connection of alarge component module on the circuit board this requirement is notalways satisfied.

From DE-A-3,248,694 there is known a further adapter system having aconductor path plate which is arranged between the test pin tips of thetest device, which are positioned in a standard manner, and the likewiseusual spring contact pins, with which the individual test points of thecircuit board are contacted. The conductor paths of this plate areprovided individually adapted to the circuit board concerned so thatwith these conductor paths, that is just as with the wires of theabove-mentioned known designs, the respective lateral offsets ofassociated test contact tips and test points on the board is bridged.With the adapter system of this publication also, for each new circuitboard a new conductor path plate with the specifically matched conductorpattern has to manufactured, and this plate also is usable as adapteronly for this board.

From EP-0374434 A1 there is known still a further test device, howeverhaving a kind of universe adapter. There, in a first adapter plate foruniversal use, there are placed, one against another, axiallydisplaceable contact pins of constant length. In an associated secondadapter plate, individual pins for the specific use are mounted inselected positions, which pins can lift up the pins of the first adapterplate arranged in correspondence to this selection and thus bring onlythese pins into contact with respective test points of the board. Thepins of the second plate are electrically connected with the terminalsof the test device by respective moveable wire connections. The secondplate provided with the pins is equipped in a manner individuallyadapted to the board to be tested.

SUMMARY OF THE INVENTION

The disadvantages mentioned above are removed with the presentinvention, which moreover offers further advantages as set out below.

The invention is a device as set out in claim 1, and furtherconfigurations of the invention are indicated in the subclaims.

The present invention resides primarily in a universally employableraster plate in accordance with the invention, associated with a testdevice, having furthermore a selection of the arrangement of contactsurfaces in accordance with the invention. Further developments relateto more specific configurations of the raster plate and specificprovisions involving the employment of special spring contact pins.

In the following description the invention will be further explained indetail and with reference to the accompanying Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an basic representation of an adapter employed with theinvention, having a raster plate in accordance with the invention.

FIG. 2 shows, supplementing FIG. 1, a particular configuration of aspring contact pin which can be employed with the invention.

FIGS. 3 to 5 show schemes of an example of a distribution/arrangement ofthe contact surfaces of the raster plate of the invention, in accordancewith the invention.

FIGS. 6 and 7 shown further schemes of modified, more specificdistribution in accordance with the invention.

FIGS. 8 to 10 shown schemes and flow charts relating to a recursiveadaptation of the distribution.

FIG. 11 shows a configuration of a spring contact pin pair employablefor special cases with the invention.

FIG. 12 shows a preferred construction of the raster plate in accordancewith the invention.

FIGS. 13 and 14 show further forms of configuration of the springcontact pin connections, in conjunction with a raster plate inaccordance with the invention.

FIGS. 15 and 16 show further configurations.

FIGS. 17 show the configuration of a further raster plate forparticularly extensive mixing of the contact surfaces of the group withone another.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Test devices 28, which have upwardly directed--in the illustration ofFIG. 1--spring contact tips 29 are known; such a contact being providedfor each channel of the test device. In accordance with the invention, araster plate 21 is provided which in accordance with one embodiment isadapted to the test device 28. This raster plate 21 has contact surfaces22 on its upper--in FIG. 1--outer surface. Further contacting surfaces27 are provided on its underside. Of these, each has electrical contactwith a respective one of the contact tips 29 of the test device 28,namely when the raster plate 21 is placed on the field of the contacttips 29.

As will be explained in more detail below, the number of contactsurfaces 22 of the upper side of the raster plate 21 is, in accordancewith the invention, n-times larger than the number of contact surfaces27 of the underside, the number of which contact surfaces on theunderside is usually provided equal to the number of the spring contacttips 29. With particular selection and configuration of thepotential--(Vcc)--and ground terminals, the indicated relationships mayhowever be somewhat altered.

On/in the raster plate 21, in each case n contact surfaces 22, as agroup No.1, No.2,. . ., are electrically connected with a respectivecontact surface of a respective terminal 27. By means of the contact ofa contact tip 29 with the contacting surface of a terminal 27 these ncontact surfaces 22 are thus connected with a respective associated testchannel of the test device. How these in each case n contact surfaces 22of one group are distributed/positioned on the raster plate 21 mixedtogether with the respective n contact surfaces of other groups--whichare connected each with one of the other contacting surfaces of theterminals 27--will be described in more detail below with reference toseveral exemplary embodiments.

It should be noted that in accordance with the invention the rasterplate 21 may also be a part of the test device 28, so that to thisextent this test device is individually configured in accordance withthe invention in this manner. The individual test channels of the testdevice are then, in a manner not previously known, directly connected tothe contacting surfaces 27 or corresponding terminals (whereby the fieldof spring contact tips 29 can be dispensed with).

FIG. 1 shows--designated by 1'--an adapter part, configured and employedin accordance with a further aspect of the invention, for the mountingof spring contact pins employed specifically for the invention, of whichtwo pins 2, 3 are illustrated here. 10, 11 and 12 designate guide holeplates specific to the invention, of which at least two are necessary,three being illustrated here, which hole plates serve for guiding thepins 2 and 3. Each of these guide hole plates has bores 13 through whichbores the spring contact pins are guided. The hole plates 10, 11 and 12are, as shown, arranged at a spacing from one another and the bores 13are positioned in the individual hole plates above one another or moreor less offset one to another. In this way, the spring contact pins 2, 3receive a predeterminable defined direction in the space between theraster plate 21 and the component assembly circuit board 31 which areboth arranged in reference to the adapter part 1, as described in moredetail. Through the defined guiding achieved by means of the bores 13,which intentionally in accordance with the invention is also inparticular obliquely directed, test points 32 of the board 31 andcontact surfaces 22 of the raster plate 21 can be connected with theinvention in each case with only a single spring contact pin 2, 3, evenif the test point 32 and the contact surface 22 (referred to the normaldirection of the board 31 and the raster plate 21) are positioned offsetlaterally one with respect to the other. This oblique direction isstable, i.e. the spring contact pins 2, 3 cannot, in accordance with theinvention, shift laterally in any way.

As can be seen from FIG. 1, such spring contact pins have obliquepositions which are very differently directed to one another.

In order to indicate an exemplary size relationship for an arrangementin accordance with FIG. 1, for example 60 mm may be mentioned for thespacing between the raster plate 21 and the component assembly plate 31.The spacing of neighbouring contact surfaces 22 of a raster plate 21 inaccordance with the invention is provided as e.g. about 1 mm. A normalraster dimension of components of the component assembly circuit boardis e.g. 1.27 mm. The two test points 32, 32' on the component assemblycircuit board, contacted in FIG. 1 with spring contact pins, to whichtest points the components 33 and 33' are connected each with arespective terminal, have in practice a spacing from one another whichis several times this raster dimension 1.27 mm. Merely for the purposeof completeness, it is noted that the component terminals at the testpoints 32, 32'. . ., as can be seen from FIG. 1, may be differentlyconfigured and that spring contact pins having correspondingly adaptedcontact ends are employed. A test device has e.g. 1000 test channels andthe number (n-times so many) of contact surfaces 22 may be e.g. 50000.How many test points 32 of the board are to be contacted depends uponthe individual case, i.e. depends upon the specific board.

The component assembly circuit board 31 is held in a mounting providedfor it (which mounting is not discussed in more detail because it isknown) so that the predetermined defined spacing to the test device 28or to the raster plate 21 is complied with, even against the springforces of a great number of spring contact pins 2, 3, . . . As mountingfor component assembly circuit boards there are usual in practicemechanically effective clamps or suction by means of vacuum techniques.For the latter case, a vacuum tight sealing below the board 31 isneeded. From the state of the art it is known to employ for this purposespring contact pins whose outer sleeves, namely as shown in FIG. 2, areplaced in a plate 112 in a vacuum tight manner. Per se, this wouldhinder the oblique positioning of the spring contact pins, namely asshown in FIG. 1, which oblique positioning is not only permitted inaccordance with the invention but represents a possibility for furtherdevelopment of the invention. For this case, there are provided for theinvention specific spring contact pins 102 which have a part piece 1002which is deflectable in terms of direction. 1012 indicates a jointwhich--because of the per se only slight necessary deflection--can berealised relatively simply e.g. as a rubber joint (with electricalbridging), as a ball joint, a spring joint and the like. Such a contactspring pin should have, above and below the fixed engagement in theplate 112, a spring contact pin, e.g. in accordance with any knownconfiguration.

Also with the configuration according to FIG. 2, there is to be providedfor the plate 112 at least one further guide hole plate 10, namely forthe pin part 1002 to be deflected.

The guide hole plates are, in accordance with the individual case,provided with bores 13 and are so rigidly connected--above one another,at a spacing from one another--that subsequent lateral displacements ofthe hole plates 10, 11, 12 (112) relative to one another are excluded.This is effected with e.g. conventional mechanical means, e.g. (notshown) connection rods 16, with which the adapter part is further alsoto be held relative to the raster plate 21, displacement-free and withdefined spacing.

Below, starting from the state of the art, a significant further part ofthe invention will be described.

In accordance with the practice of the state of the art, in order toconnect a particular test point of an component assembly circuit boardwith the contact surface of a suitable test channel of a test device,the above explained spring contact pin pairs with wire connection areemployed in the state of the art. Thus, it represented no real problemto find in the vicinity of the test point, at least in the widervicinity of the test point, such a test channel from amongst the testchannels offered by the test device which is not already otherwiseoccupied, whereby lateral offset of the test point and the associatedcontact surface of the test channel one to another was not a significantconsideration. Such an offset of test point and contact surface relativeto one another can, in accordance with the state of the art, be up to ahundred times the raster size without difficulty. Clearly such isimpossible for an adapter part in accordance with the invention, havingonly single spring contact pins, since these--as can also be seen fromFIG. 1--allow only slight lateral offset of the test point and thecontact surface to be connected with one another, i.e. permit onlyslight oblique positioning of the--in each case only single--contact pinemployed therefor.

In accordance with an embodiment of the invention, however, there are tobe worked with (in substance) only such single spring contact pins asshown in FIG. 1. The advantage of this limitation lies in that theplacement of the spring contact pins in the adapter part 1--consistingof at least two hole plates 10, 11, 12--is very substantially simplifiedrelative to the assembly of a known adapter part with the spring contactpin pairs placed therein. A matter to be taken into account is thatadapter parts associated with particular component assembly circuitboards have to be stored in production plants, but with theinvention--for reasons of costs saving--these adapter parts can also bekept without spring contact pins located therein. The spring contactpins, which represent a not insignificant investment, are advantageouslyused in the interim or re-employed many times, and are also employedagain in an adapter part in which they have already been used at sometime in the past.

With knowledge of the invention it is clear that such externally smoothspring contact pins as are shown in FIG. 1 and as are employed in theinvention can be placed into a prepared or already available adapterpart with very little effort, and after use of this adapter part canalso be just as easily removed again. The putting in place can beeffected in simple manner in that one slides a bundle of spring contactpins, upright, above the for example upper hole plate of the adapterpart and allows one of the spring contact pins of the bundle to fallinto each individual hole of this (upper) hole plate.

Above, it is already indicated that with the invention there isassociated with each channel of the test device in each case an n-timesgreater number of contact surfaces 22 on the raster plate 21. This, andthe distribution of these contacts surfaces 22 described below--forminga further aspect of the invention--serves the purpose of making possiblethe preferred, advantageous, practical and where possible exclusiveemployment of only single spring contact pins 2, 3.

There can be provided many schemes of arrangement for the distributionamongst one another of the contact surfaces 22 of different testchannels, with which the presence or accessability of or to theindividual test channels of the test device can be made more or lessevenly distributed over the whole surface of the raster plate 21. Withmore or less uniform distribution of the accessability of the testchannels on the raster plate 21 it is possible to achieve that from anytest point 32 (of any board 31 to be tested)--in its vicinity (below),on the raster plate--a contact connection with one of many selectabletest channels can be established with one single contact pin 2, 3. Inorder to realize this, there is provided with the invention (as alreadyindicated in FIG. 1) that such single spring contact pins 2, 3 areemployed also in oblique position, namely retained obliquely by means ofthe adapter part 1'. Clearly, however, only a degree of maximum obliquepositioning to be predetermined can be allowed.

A predetermined degree of maximum oblique positioning of an individualspring contact pin 1, 2, . . ., i.e. a tolerable degree of lateraloffset, is for example restricted to plus/minus the (diagonal) rasterdimension of the contact surfaces of the contact plate 21, i.e. forexample restricted to the amount plus/minus 1,4 mm. That means that forexample starting from a test point 32 to be connected with a testchannel, by means of the spring contact pin 2, 3,. . . only the contactpoint lying (substantially) vertically therebelow and selectively one ofthe eight further contact points present in the surface which directlysurround this contact point vertically below, can be contacted. Thismeans that, taking into account the above-mentioned restriction,starting from this test point 32 selectively nine contact points 22 canbe aimed for. Thus, if the contact point 22 lying vertically below thetest point 32 is that of an already occupied test channel (or a testchannel which for circuitry reasons cannot be employed here)--whichchannel is thus not available--or if this is a Vcc or ground terminalconnected with no test channel, then with the spring contact pin--bymeans of selected positioning of the bores 13 in the hole plates 10, 11,12 (as shown in FIG. 1)--starting from the test point 32 there can becontacted a neighbouring contact surface 22 of another test channel.

FIG. 3 shows as a first example an arrangement or distribution of thecontact surfaces of a raster plate configured in accordance with theinvention, which arrangement or distribution is generally preferred forthe invention. The raster plate--assumed to be quadratic merely for thepurpose of simple explanation--is conceptually divided into the foursectors A/B, B/C, C/D and D/A. At the outer edge of the sector A/B, onequarter (=a) of all test channels available are connected. In FIG. 3,merely by way of example, only 20 channels a₁ to a₂₀ are indicated forthe sector A/B. A further quarter of the available test channels b₁ tob₂₀ are connected at sector B/C. The like applies to the two furthersectors. In the sector A/B one half of the contact surfaces 22 presentthere are connected with channels a₁ to a₂₀ and the other half areconnected with other test channels, here for example with the testchannel b₁ to b₂₀. This means that in the sector A/B contact surfaces 22of the channels a₁ to a₂₀ and b₁ to b₂₀ are accessible, and are alldistributed amongst one another. In sector A/B it is thus possible, withthe inclusion of an oblique positioning of the respective single springcontact pin, to provide contact connections from test point 32 to thehalf of all available channels, with such a single spring contact pin 2,3. In sector B/C there are available, in the same manner, the contactsurfaces of test channels b₁ to b₂₀ and c₁ to c₂₀, whereby the channelsc₁ to c₂₀ are connected for example at the outer edge at the sector C/D.The like applies to the sectors C/D and D/A. In sector C/D contactsurfaces of the test channels c₁ to c₂₀ and d₁ to d₂₀ are available, andin sector D/A contact surfaces of the test channels d₁ to d₂₀ and a₁ toa₂₀ are available. Clearly, in two neighbouring sectors taken together(e.g. A/B and B/C) contact surfaces of three quarters of all testchannels present are available. Such a distribution amongst one anotherof the contact surfaces associated with the test channels is, in thesense of the invention, a sufficiently even distribution even if, as canbe seen, regions of the raster outer surface can be indicated in whichnot all channels present are available next to one another. This isvalid for the invention also because, in accordance with a furtherdevelopment of the invention, there is additionally made available arecursive selection process.

FIG. 4 shows, as a detail, how in accordance with a preferred furtherconfiguration of the exemplary embodiment of FIG. 4, the test channelscould be distributed with their respective multiple contact surfacesdistributed in the plane, within a respective sector.

FIG. 4 shows for the sector A/B how the contact surfaces of the testchannels a₁ to a₂₀ and b₁ to b₂₀ can be advantageously distributedamongst one another linewise and line-nested. The lowest line of sectorA/B in FIG. 4 contains, next to one another, contact surfaces of thechannels a₁ to a₂₀. The second line, lying thereabove--lying furtherinwardly and thus shortened in its length contains the contact surfacesassociated with the test channels b₁ to b₂₀, designated in FIG. 4 withthe numbers 21 to 40, except for the contact surfaces No. 27 and No. 34which (due to the shortening of the line) are introduced into the linelying next above, the third line. Further, this third even shorter lineagain contains contact surfaces No. 1 to No. 20 belonging to thechannels a₁ to a₂₀, except for six contact surfaces which are alreadyintroduced into the line thereabove, the fourth line. The fourth lineand in the case of this example the fifth line completely, againcontains contact surfaces No. 21 to No. 40 of the group of the testchannels, b to b₂₀.

It is to be taken into account that in practice the number of thechannels and thus the number of the contact surfaces is very muchgreater and thus the distribution is very much finer than it might beassumed on the basis of the simplified example of FIG. 4.

In the component assembly circuit board to be tested, for some testprocesses the part regions to be individually tested must becontrollably supplied with electrical voltage, and this generallywithout other part regions--which are not at the moment to betested--being placed in operation through applied voltage. It iscorrespondingly useful, just as one contacts individual test points,also to effect earthing and the current supply from the test device intothe board to be tested by means of spring contact pins. For thispurpose, some contact surfaces are connected with ground or withoperating voltage (controllably fed from the test device). Thus,together with the above-described distribution of the contact surfacesand test channels with one another, there is also the distribution ofground and potential terminals. For example then, instead of theabove-indicated nine selection possibilities there may be available e.g.only eight possibilities and the ninth possibility is reserved for thevoltage supply. However, this constitutes no practical restriction ofthe utility of the invention, since the possibilities for variationavailable in accordance with the invention are very large.

Again as a detail, FIG. 5 shows a distribution corresponding to FIGS. 3and 4, in which contact surfaces also for earthing and current supplyare taken into account in an exemplary manner. Again, the lowest linecontains contact surfaces of the channels a₁ to a₂₀, namely thosedesignated No. 1 to No. 20. The contact surfaces No. 21 to No. 40 are associated with the test channels b₁ to b₂₀. Contact surfaces with thenumbers 41 to 60 are associated with the test channels c₁ to c₂₀. Thesecontact surfaces are contained in sector B/C which extends from theright vertical edge of the illustration in FIG. 5 towards the centre inthe manner of a triangle. It can be seen from FIG. 5, as alreadyindicated above, how within the lower/right diagonal half of the rasterplate 21 of FIG. three quarters of all available channels are presentwith contact surfaces distributed amongst one another.

FIGS. 6 and 7 show a second example, additional to the example of FIGS.3 to 5, of a distribution of the multiply present contact surfacesassociated with the individual test channels. The scheme of FIG. 6 has alesser uniformity of the distribution of the contact surfaces of theindividual test channels , but has the advantage that the electricalconnections of the individual distributed contact surfaces to theirassociated test channel terminals--to be provided on/in the rasterplate--can be effected in a manner which keeps them relatively short. InFIG. 6, a₁ to a₈ designate the connections of eight test channels of afirst group. The connections of test channels of further groups aredesignated with b₁ to b₈, c₁ to c₈ and d₁ d₈ . The contact surfacesassociated with the individual test channels are represented by blackfilled points which, as can be seen from the Figure, are connected withtheir test channel terminal through short electrical paths. As canfurther be seen from the Figure, and requiring no further explanation,the contact surfaces of different test channels are distributed amongstone another in their vicinity. Such a less evenly distributedarrangement of the contact surfaces of the test channels is advantageouswhen very short connections between the test channel terminal and thetest point 32 of the board is significant. Only the short conductorpaths and the single spring contact pins form the overall length of theconnection between test channel terminal and test point.

FIG. 7 shows a scheme very similar to that of FIG. 6 however with--asindicated by a few designations of the contact surfaces here representednot filled in black--a more extensive distribution of the contactsurfaces amongst one another in comparison to FIG. 6. With the exampleof FIG. 7, however, the connections of the contact surfaces are in partalready somewhat longer. It is to be considered for each individual casewhat degree of uniformity of the distribution on the one hand and on theother hand minimized length of the connections on/in the raster plate ismore favourable for the solution of the individual problem.

In dependence upon the individual case, and also in dependence upon thenumber of the test points of a board in comparison with the overallnumber of available test channels, the situation can arise that for atest point 32 of the board there is available no suitable test channelin the neighbouring region (attainable with a single spring contact pin)This unavailability arises when all contact surfaces of theneighbourhood of such a test point belong to test channels which arealready occupied at other places of the raster plate, namely because thetest channels are present also at those other places with associatedcontact surfaces and are already contacted with other test points.

In accordance with a further development of the invention, the followingsolution of the problem is provided. If in a region of mutuallyneighbouring contact surfaces lying under the test point 32 no contactsurface can be found whose test channel is still free, one can in arecursive manner seek in another region, in which one of these testchannels is already contacted on its contact surface and occupied, for apossibility--through repositioning of this contact, i.e. by means ofdirecting the spring contact pin located there to another contactsurface of a test channel which is still free--to make free thepreviously occupied contact point. Thus, there is then provided in thefirst-mentioned region of the test point 32 a contactable contactsurface. of a test channel which has now become free. Naturally, thisselection, as will be described in more detail below, is calculated inadvance "on paper", i.e. in terms of software, for example in acomputer, and only then at the end are the guide hole plates 10, 11, 12bored. Merely by way of further explanation it is mentioned that if e.g.in the first recursive step still no contact point, i.e. no test channelcan be made free, one goes to another region in which the test channelof another contact surface of the region of the test point 32 can bemade free. One can, however, effect an even further recursivemaking-free, recursively in the region in which one could not make freethe desired test channel.

FIG. 8 serves for further explanation of the recursive process of thedistribution algorithm. It is assumed that in the device in accordancewith the invention a (respective) spring contact pin can be setobliquely up to the extent of one diagonal raster spacing 1 of thecontact surfaces of the raster plate. It is further assumed that in theregions considered--the regions I, II and III illustrated in theFigure--the middle one of in each case nine mutually neighbouringcontact surfaces is a ground terminal or a potential terminal. Now, ifthere arises the case that a test point 32 lying thereabove (see alsoFIG. 1) should be contacted with one of the test channel contactsurfaces of field I by means of a spring contact pin and the testchannels belonging to these further eight contact surfaces of the regionI are already occupied elsewhere in the overall field of the contactsurfaces of the raster plate, it is attempted for example to make freethe contact surface No. 1, in that it is attempted--at that point of theoverall raster plate at which the test channel belonging to this surfaceNo. 1 is occupied--there to alter this occupation. If this occupation ispresent for example in region II, then in that region the contactsurface No. 1 connected with this test channel is made free in that inthe region II instead for example the (still free) test channel ofcontact surface No. 2 is occupied. Thus, since in the region II thecontact surface 1 there--and thus the associated test channel--is nowfree, the contact surface 1 of the region I is then available forcontacting with the spring contact pin which effects the connection withthe test point 32 of the board. If, in an extreme case, the contactsurface No. 1 in region II cannot be made free in the manner justdescribed--because the test channels of all other illustrated contactsurfaces are there likewise already occupied--one proceeds then toeffect an altered occupation of the above kind in still a further regionIII, for example from the contact surface No. 2 to for example thecontact surface No. 3, of another, still free test channel. This alteredoccupation makes free in region II the test channel of the local contactsurface No. 2, namely thereby to make free in region II the test channelof contact surface No. 1. This is the recursive procedure. Naturally,one might instead attempt also the step I→III, namely to attemptdirectly in region III to make free the test channel of the contactsurface No. 1 as explained: this however only when the region IIIincludes a contact surface No. 1 associated with this test channel.

This only apparently complicated procedure is carried out by means of acomputer, in which a corresponding selection and search program isentered. The flow chart scheme of FIG. 9 indicates such a program withreading-in and pre-sorting of input data, whereby this data is thecoordinates of the test points of the component assembly circuit board.The presorting takes into account for example criteria such as may besignificant due to internal structures of the testing system. In thenext step there is effected the selection of the best conflict-freecontact position on the raster plate for a given test point. When thishas been effected, there is effected the same selection for the testpoint next to be connected. If, finally, all test points are arranged,the calculation of the coordinates for the bores 13 in the guide holeplates 10, 11, 12 can be effected and can be carried through in furtherprocessing. If free test channels cannot be found for all test pointcontact surfaces, the program returns again to the selection step, inorder to find better contact positions. The flow chart of FIG. 10indicates the scheme of the already above-described recursive procedure.First, a selection of a contact position (in a region I) is made, whichis attainable with an obliquely positioned spring contact pin. This is aposition of a first order. If a free position is found, the scheme thenimmediately transfers the selected contact position to the main programof FIG. 9. If no free position can be found, there is effected aselection of a contact position by means of repositioning in anotherregion II, III already having occupied contact positions (positions ofhigher order), namely in order to create a free position in the regionof direct accessability (position of first order). Then the schemetransfers the selected position to the main program.

With test devices for which--as a result of their internal structure(e.g. multiplexed pin electronics)--certain restrictions with regard tothe arrangement between test points and test channels are predetermined,then in the selection of the contact surfaces the rules predetermined bythe manufacturer of the test device must be maintained. The selectionprocedure is effected in this case in the same manner. However, in theselection, in addition to the criteria that the test channel is notalready occupied, the criteria is also considered as to whether thearrangement rules of the test device are fulfilled.

In an extreme case--such a case could for example appear in the regionof a plug-in component group having many plug-in limbs--an auxiliarymeasure can be carried out which is shown in FIG. 11. This extreme casecan appear more frequently when--in particular for electricalreasons--raster plates 21 are employed which for a predetermined numberof contactable test channels have an n-multiple of this number ofcontact surfaces 22, with which the number n is selected to be lesslarge. This measure is a spring contact pin pair having, however, incontrast to the state of the art, extraordinarily short electrical wireconnection extending only over few raster lengths of the raster plate.The pin 202 provided on one side with a spring contact is connected viathe conductive wire 205 with the second spring contact pin 203. At therespective other ends of the pins 202 and 203 there are providedelectrically insulating bodies 204. The spring contact pins 202 and 203there support themselves on the plates 21 and 12. With such a springcontact pin pair it is possible to bridge over several raster lengths,in contrast to which with the generally provided obliquely directedspring contact pins 2 and 3 only a displacement as far as plus/minus oneor two raster lengths (transversely and in the diagonal) can beeffected. This auxiliary measure does not conflict with the principle inaccordance with the invention because on the one hand it serves only tooffer a solution for cases appearing solely in special situations and onthe other hand is compatible with regard to the guide hole plate of theadapter part provided in accordance with the invention.

With the invention there are to be provided, as already mentionedseveral times above, electrical connections in/on the raster plate 21from the contact surfaces 22 located on its outer surface to points,e.g. to the mentioned contacting surfaces 27. It is particularlyexpedient to effect these connections as conductor paths.

FIG. 12 shows, in sectioned side view, a raster plate 21 of amulti-layer construction, provided in accordance with a furtherdevelopment of the invention. Again, the contact surfaces provided onthe external surface (here upper surface) of the raster plate 21 aredesignated with 22. 121 to 125 designate layers or the like ofelectrically insulating material. The raster plate 21 has bores,designated by 131, associated with the contact surfaces 22. Between thelayers 122 and 123, and between 124 and 125 there are provided in thisexample metallisations 132 and 133 which extend continuously over thesurfaces, which metallisations are provided for the connection anddelivery of ground potential and current supply potential Vcc. Betweenthe layers 121 and 122 on the one hand and between 123 and 124 on theother hand there are illustrated a number of conductor paths 141, 142,143. In order for example to electrically connect the contact surface22, with the metallisation 132, namely with the ground connection, it isprovided that the bore 131 belonging to this contact surface 22₁ ismetallized on its inner walls in such a manner that, and themetallisation 132 is brought so far up to this bore that, via thisinternal metallisation 136 of the bore electrical connection isestablished between the metallisation 131 and the contact surface 22₁.The like applies to the contact surface 22₂ with an internal wallmetallisation of its associated bore 131 and a contact connection withthe metallisation 133 of the Vcc terminal. There where no electricalconnection from the metallisations 132/133 to contact surfaces 22 shouldbe present, these metallisations are expediently removed or recessed inthe shape of a ring, around the bores 131' concerned.

For, e.g. conductor path connections 141 and 142 running in thedirection of the horizontals of the plane of FIG. 12, the plane betweenthe layers 121 and 122 is for example reserved. There, for examplecontact surfaces are provided--designated on the one hand 22₃ and 22₃and designated on the other hand 22₄ and 22_(4') --which are each to beelectrically connected by means of the conductor path connections 141and 142. For this purpose, the internal walls of the bores 131 concernedare metallised, so that between the conductor path 141 and therespective contact surface there is an electrical connection. Further,the bores associated with the contact surfaces 22_(3') and 22_(4') arefurther electrically conductively metallised up to the associatedcontacting surface 27 of the respective contact tip 28 of the testdevice 29. It can be seen that therewith the electrical connection fromthe respective contacting surface 27, i.e. the terminal for the testchannel of the tip 29, to the two electrically parallel connectedcontact surfaces 22₃ and 22_(3') is provided. The same applies for thecontact surfaces 22₄ and 22_(4'). This corresponds to an n=2-timesmultiplication of the test channel terminals on the outer surface of theraster plate 21. In accordance with the invention, in general then-times multiplication is selected to be much greater.

The plane between the layers 123 and 124 is reserved, in similar manner,for conductor paths 143 which run in vertical direction with regard tothe plane of FIG. 12, i.e. which in substance cross the direction of theconnections 141/142.

Also for the conductor path connections 143 there are providedcorresponding internal wall metallisations of the bores, for electricalconnection of contact surfaces 22 with contacting surfaces 27.

Such conductor path connections 141, 142, 143, and also the connectionsof contact surfaces which are be brought to ground or Vcc potential withthe ground-/Vcc-terminals are--in comparison with the wire connectionsemployed in accordance with the state of the art in known testdevices--sensitive with regard to overloading. In accordance with afurther development of the invention, there are provided protectionelements 150 for the conductor path connections of the raster plates.These may be protection elements in the manner of fuses, which arearranged for example on the lower outer surface of the raster plate 21between the internal wall metallisation of a bore 131' and therespective contacting surface 27 (for the connection of the test tip28). There, a blown fuse 150 can be repaired purposefully using knownmethods. Such overloadings can appear when a defective componentassembly circuit board is tested.

This above-described configuration of raster plate 21 provided inaccordance with an aspect of the invention may, as already mentioned inthe introduction, be a separate adapter part for a known test device ormay also be an integral part of a test device which is then new to thisextent. In this case, the contacting surfaces 27 and the contact tips 29of the test device--which contact tips represent a not insignificantcost factor--can be dispensed with and direct electrical wireconnections from the terminals of the individual test channels to theinternal wall metallisations of the respective bores 131' of the rasterplate can be provided.

Above, a normal practice is mentioned; to act with suction on thecomponent assembly circuit board 31 by means of vacuum and with the aidof atmospheric pressure to press the board onto the large number ofspring contact tips, in order to ensure the desired contact between thetest points of the board and these spring contact tips. For this purposethere is needed an upper plate 112 of the adapter which is stableagainst bending, such as is already shown in FIG. 2.

FIG. 13 shows an alternative configuration of spring contact pins to beemployed in relation to the raster plate 21 in accordance with theinvention. Similarly to the configuration of FIG. 2, there are providedspring contact pins 302 which are placed in the adapter plate 112fixedly and vacuum-tight. With the upwardly projecting spring tips,these pins contact the respective test points of the board (as shown inFIG. 1). The opposite end of these spring contact pins 302 is formed asa contacting end 303. As shown in FIG. 1, the further contact connectionto the contact surfaces 42 of the raster plate 21 is effected by meansof spring contact pins 2, 3 of the above-described kind. These springcontact pins, guided by the hole plates 10, 11, 12 can--as with theexample of FIG. 1--contact selected contact points 22 in obliquedisposition. After use of this adapter, the spring contact pins 2 can beagain removed in a simple manner from the hole plates 10, 11 forming theadapter part--which hole plates as with the example of FIG. 1 are placedin the test device, mechanically rigidly connected with one another--andcan be further employed in another adapter. As in the state of the art,also the fixedly placed contact pins 302 can be again employed orfurther employed if one pulls them out of the plate 112 again.

A still further configuration for the invention is a primary toexclusive employment of spring contact pin pairs of similar form to thatalready shown in FIG. 11. As already mentioned above, such springcontact pin pairs are advantageously to be employed when the rasterplate 21 in accordance with the invention has a not very largen-multiple number of the contact surfaces 42. Such spring contact pinpairs 202', 203 can be employed with short and with longer electricalconnection wires 205. With the configuration illustrated in FIG. 14, theupwardly directed spring contact tips 202' are placed vacuum-tight in anadapter plate 112 which is sufficiently stable for suction of the board,and are retained in the plate.

Despite the employment of the spring contact pin pairs 202', 203' thisconfiguration also offers most of the advantages which are provided dueto the raster plate 21 in accordance with the invention having amultiplied number of contact points 22, namely with regard to the numberof test tips of the test device which are present. Precisely as a resultof the possibilities of access to contact surfaces 42--multiplied inaccordance with the invention n-times in number and also distributedamongst one another--of the predetermined smaller number of testchannels, this configuration using pin pairs also offers the advantagein each case of making do with very short connection wires 205.

The above configurations provide in substance electrical wireconnections between specifically provided (spring) pins only inindividual cases or with individual positions (FIG. 11, 13 and 14). Forthe raster plate 21 there are preferably provided, corresponding to theexamples so far described, conductor path connections between thecontact surfaces 22 of one outer surface (upper surface) of this rasterplate--generally present in n-times multiplicity--and the contactsurfaces of the terminals 27 of the other (lower) outer surface.

However, for the manufacture and/or the employment of the rasterplate--which is in accordance with the problem to be solved and inaccordance with the invention universally employable--it may beadvantageous to replace these conductor path connections eitherpartially in particular completely by means of electrical wireconnections. In particular with this measure there is reduced the effortrequired for the design of the connection pattern relevant to theinvention, for the above-mentioned connections between in each case then-multiplied contact surfaces 22, distributed over the one outer surfaceof the raster plate, with the associated respective contact surfaces ofthe terminals 27 of the other outer surface. In accordance with theinvention, the parallel-connected contact surfaces 22, present n-times,which are associated with one contact surface of a respective terminal27 of the other side of the raster plate, are positioned on the oneouter surface of the raster plate within at least one region of thisouter surface having further n-times contact surfaces, which in eachcase are associated with other contact surfaces of the terminals 27,mixed in with one another.

With wire connections there can namely be effected practically arbitraryelectrically isolated crossings with wire connections of other contactsurfaces, which is unfortunately not the case for conductor pathswithout further measures or can only be achieved in a complicatedmanner. Above all, with such wire connections there can be realized forthe n-multiplied contact surfaces 22, associated with the respectiveterminals 27, even greater inter-mixing over even wider areas or overthe entire surface of the raster plate 21.

Below, there will be described an example of an raster plate 21' inaccordance with the invention having electrically contacting wireconnections and a process for the manufacture of such a plate.

FIG. 15a shows two plates 1210 and 1211 provided for a complete rasterplate. The first 1210 of the two plates has bores 71 of the number ofand freely selectable positioning of the contact surfaces 22 of a rasterplate 21 employed for above-described examples. The second plate 1211has the bores 72 which are present in a number corresponding to that ofthe contact surfaces of the terminals 27. The positions arepredetermined as above by the (standardised) test device 28 and itscontact pins 29.

In the initially larger spacing A of the two plates from one another,there are placed into the e.g. first plate 1210, as for example shown inFIG. 15a, into the prepared holes 71--preferably clamped in or pressedin--shaped contact pins 73 preferably having a head for a contactsurface 22. Such a contact pin 73 has e.g. an axial bore in the pin partthrough which a thin conductor wire 77 is or is to be drawn. This wireis applied in or on the pin 73 in an electrically contacting manner,e.g. soldered on, and has an electrically insulating cover.Alternatively, the respective wire 77 can also be attached in acontacting manner solely at the (lower) end of the pin 73.

As illustrated in FIG. 15a, this respective wire 77 is or is to befurther laid through a hole 72, determinable and to be selected, of thesecond plate 1211, whereby in general in each case there is provided alateral offset, of greater or lesser size, of the hole 71 to the hole72. In accordance with the provided or predetermined distribution of thecontact surfaces 22--in accordance with the invention--in positions onthe raster plate which are--in accordance with the invention--mixed withand amongst one another, here on the first plate, the wires of the pinsor of the contact surfaces 22, which are namely present consequently inn-times multiple and which are associated in accordance with theinvention with a respective contact surface 27 of the opposite outersurface of the raster plate, are taken to the respective hole 72 of thesecond plate, in particular are taken through this hole. The wires ofthe respective hole 72 are then attached and connected in electricallycontacting manner, in particular soldered in, with the respectivecontact surface of the terminal 27, as will also be described in moredetail below. Because of the n-times multiplicity of the contactsurfaces 22 with regard to the contact surfaces 27 predetermined by thetest device, there are taken to, e.g. through, each respective hole 72of the second plate the number n of wires which are there consequentlyelectrically connected with one another. FIG. 15 shows an example withn=3.

It can be seen from what is described above and from FIG. 15b that forthe electrical connections of the n-multiple, parallel-connected,contact surfaces 22 of a group No. 1, No. 2, . . . with the respectivecontact surfaces of the terminals 27 which are associated with thecontact surfaces 22 of such a group, in each case electrically connectedtherewith, there can be effected practically any arbitrary crossingconnections of the wires 77. For ease of understanding and solely by wayof example, FIG. 15b shows the wiring of individual contact surface 27₁and 27₂ each with three pins or contact surfaces 22₁ and 22₂ positioneddistributed amongst one another. In practice, there are located betweentwo contact surfaces 22 of one group a multiplicity of contact surfaces22 of other groups.

Expediently, after wiring of these two plates 1210 and 1211 has beeneffected as described, these plates are moved towards one another, i.e.their spacing A shown in FIG. 15a from one another is reduced. The wires77 can then also be tightened by pulling and advantageously also thesolder contacting to the contact surfaces of the terminals 27 iscorrespondingly only thereafter carried out. The intermediate space thenstill provided, with the connection wire 77 contained therein, can thenbe filled e.g. by casting in with casting resin 78, or there is effectedsome other fastening of the first and second plates with one another.This then provides a raster plate 21' equivalent to the raster plate 21.This raster plate 21' is equally universally employable, i.e. is notindividually adapted to a particular circuit board to be tested, and canbe variously employed just like the raster plate 21.

FIG. 16 shows a specific configuration which can be employed as afurther development for in particular a configuration in accordance withFIG. 15b but which can also be used in accordance with configurationsdescribed earlier. In particular with very extensive mixing of thepositionings of the contact surfaces 22 amongst oneanother--advantageous for universal applicability--it arises thatcorresponding to the lateral offset of a respective contact surface 22to the associated contact surface of the terminal 27 relatively longconnections are also necessary. This applies in particular for themeasure with wiring connections as per FIGS. 15a/15b, with whichpractically unlimited mixing of the contact surfaces amongst one anotheris possible. Such long connections may, however, function as antennasand bring about capacitative disruptions of the individual testchannels. This further development is advantageous in particular forcases with very high frequency test signals of the test device 28.

The further development in accordance with FIG. 16 provides, for dealingwith such a case, to divide the contact surfaces of the terminals 27, asshown, into a plurality of part contact surfaces 27_(x) lying near toone another in the surface. In FIG. 16, in each case two part contactsurfaces 27₁ and 27₂ are visibly illustrated, whereby two further partcontact surfaces are hidden behind them. FIG. 16a shows in relationthereto, in a detail view from above, this exemplary four times divisionof a contact surface of a terminal 27.

With (spring) contact pins 81--as illustrated by way of example--whichin accordance with this further development are preferably formed to besomewhat pivotably retained, preferably biaxially pivotably (asindicated in the Figure for one axis) there can be selectively set aconnection between a respective one of the part contact surfaces 27₁,27₂. . . to the test input 29 of the test device 28 concerned. Due tosuch a division of the contact surface of the terminal 27 it can beattained in accordance with the illustrated example that the respectiveconnection provided from a test input 29 of the test device 28 to theselected contact 32 of the circuit board 31 to be tested is so formedthat in each case only one quarter of the electrical connectionspresent--e.g. the connection wires to the n-multiple contact surfaces 22in the raster plate--are electrically connected to this test input 29.Thus, with this further development of the invention, only this onequarter of the n-multiple connections to contact surfaces 22 can in anyevent have a disruptive effect. Depending upon the effort requiredand/or the expediency of the measure there can be provided a moreextensive division. Such part contact surfaces 27₁ . . . are mostsensibly or as a rule divided in the outer surface of the raster platecorrespondingly two-dimensionally, e.g. four times, five times, ninetimes and the like, at a close spacing from one another. It is expedientto provide a biaxial joint 82 or the like for each respective pin 81.

The pivotable pins 81 are (as FIG. 16b shows as a detail for one pin)held in a guided manner, e.g. by means of an additional hole plate 82.This hole plate 82 is manufactured--in accordance with the selection ofthe used part contact surfaces in each individual case--withcorrespondingly positioned guide holes 83. This additional hole plate isno longer universally employable in the manner of the raster plate 21,21'. This is, however, no restriction of the invention since the smalloutlay for the specific additional hole plate is largely balanced in therespective case of need through the advantage of reduced "antenna"effect.

The pivotable contact pins 81 are as a rule part of the test device 28and the additional hole plate 82 is then employed for a specific circuitboard together with the already described plates 10, 11, or is madeavailable or stored for use in the respective case of employment.

There can also be provided an actuator-controlled selective directing ofthe pins 81. With the respective actuator there is attained an angledirecting which can be controllably set e.g. by means of a program.Instead of storing a specific hole plate for a specific circuit board,in this case the specific control program of the pins 81 for aparticular circuit board is stored.

FIGS. 3 to 5 relate to schemes for the mixing amongst one another of thepositions of contact surfaces 22 associated with various terminals 27.With these examples, the pattern of distribution is conceived startingfrom the edge of the surface and running towards the middle. FIGS. 17a,17b relate, in contrast, to a further new distribution scheme whichprovides internal lines to the individual group-wise n-multiple,parallel-connected, contact surfaces 22 of the outer surface of theuniversally employable raster plate, which lines run cross-wise of oneanother, in particular diagonally, in different planes of the rasterplate.

FIGS. 17a and 17b show two planes having conductor paths 91 and 92. Thescheme with the conductor paths 91 of one plane and the scheme of theconductor paths 92 of the other plane lie, in practice, one above theother in the raster plate 21. There are provided in the respectiveplanes, as shown, electrical connections with respective terminals 93from the respective line 91/92 to the contact bore 1133 concerned. Thesecontact bores are seen in section in the Figures and they have internalmetallisations as electrical conductors. These internal metallisationsextend as a rule up to the outer surface of the raster plate on whichthe numerous contact surfaces 22 are located. By way of thesemetallisations of the bores 1133, a respective number of contactsurfaces 22 of the outer surface of the raster plate 21 is thus alreadyconnected with the respective line 91/92 via respective terminals 93 (inthe plane concerned). Additionally thereto, or contained under thecontact surfaces 22, are bores to such contact surfaces as are providedfor the ground terminal or the terminal of supply voltages Vcc, andwhich may also be connected in some other way, e.g. to still a furtherinternal contacting plane of the raster plate 21.

FIG. 17c shows a further plane, lying in the raster plate closer to theouter surface with the contact surfaces 22. FIG. 17c also shows in theillustration non-filled circles which in each case indicate thecross-section of further bores in the raster plate 21 which respectivelyextend less deeply. These bores 1134 extend e.g. only two layers deepinto the plate and thus do not reach the planes of the connection lines91/92. As can be seen, these further bores lie between the positions ofthe bores 1133 in the regular distribution of the provided contactsurfaces 22 of the outer surface of the raster plate. With furtherconnections 95 in this plane, as shown in FIG. 17c, individual bores1133 are electrically connected with bores 1134 in the interior of theplate.

FIG. 17d shows in side view in pure schematic representation thedisposition of above described planes of conductor paths and bores 1133and 1134, as they are described above. The internal metallisationsextend as far as the edges of the bores are illustrated with thicklines. It can be understood from the illustration of FIG. 17d howdifferent contact surfaces 22 present on the outer surface of the rasterplate 21 can be connected in the interior of the plate to the individualdescribed planes i.e. to lines 91/92 present in these planes. Betweenthe plane of FIG. 17c and the outer surface with the contact surfaces 22there is indicated a further plane 17c' which may be additionallyprovided and which in its configuration corresponds in principal to FIG.17c, but which however has conductor paths directed orthogonally to FIG.17c. With 17m there is also taken into account a further metallisationplane (as mentioned above). It is to be noted that FIG. 17d can onlygive a schematic illustration since it cannot reproduce the seconddimension of the plane, perpendicular to the illustration, over whichthere extends the distribution of connections of the internalmetallisations of the different bores.

As can be seen from a comparison of FIG. 17a to 17d, the conductor lines91/92 run in the raster plate at locations of the bores 1134 beneath thedepth of those bores. Due to the lesser depth of the bores 1134 and thegreater depth of the bores 1133, with this configuration of the rasterplate in accordance with the invention, there can be obtained space forthe conductor paths 91/92 running diagonally (FIG. 17a/17b) to theraster of the contacts 22, whereby these conductor paths can in eachcase run from edge to edge of the entire raster plate, but can also,however, (as FIG. 17a/17b show) be electrically interrupted.

FIG. 17e shows how a respective bore 1133' can also serve as connectionof a conductor path 91 of the one plane with a conductor path 92,running at right angles thereto, of the corresponding other plane. Withsuch internal connections between transversely running conductor paths91 and 92 of the two planes, the n-multiple contact surfaces of arespective group--distributed over the entire surface of the rasterplate (associated with a respective terminal 27) can be electricallyconnected with one another and with this associated terminal 27 despitegreater spacings amongst them one from another.

It is apparent that in accordance with such a principle the mostextensive freely selectable connections of lines 91/92 via bore contactsand lines 93, 94 and 95 can be provided, in order to be able to arrangethe contact surfaces 22 of the outer surface of the raster plate--whichare group-wise (No. 1, No. 2. . .) associated with a respective otherterminal 27--practically arbitrarily mixed amongst one another,positioned distributed over this outer surface. Despite the small rasterof contact surfaces 22, this configuration offers sufficient space forthe numerous conductor paths.

The contact surfaces of the terminals 27 are located at the (in theFigures) underside of the plate. These terminals are electricallyconnected with respective ones of the through-going bores 1133 which aremetallised as far as the underside of the plate.

With the invention, and in particular with the particularly advantageousabove-described multilayer distribution scheme, having crossingconductor paths 91 and 92, there can be found practically in any partialregion of the overall upper surface of the raster plate containing thecontact surfaces 22 a contact surface which makes it possible to realizea connection from an arbitrarily positioned test point 32 of a specificcircuit board 31 by way of spring contact pins 2, 3 (see also FIG. 1) toa test input 29 of the test device 28, even when this test input (asseen in FIG. 1) is significantly laterally offset relative to thespecific test point 32 of the circuit board 31. As a result of theintermixed n-multiple presence of contact surfaces of a respectiveterminal 27 or of a respective test input 29 there is made available thepossibility of contacting connection from practically any point of thecircuit board to any input of the test device. This is made possible bymeans of the raster plate 21, 21' which is universally employable due tothe configuration in accordance with the invention. To emphasize thefact once again, this raster plate is not restricted to employment witha specific circuit board and not restricted to employment with aspecific test device whereby, with regard to the relationship of rasterplate and test device to one another there must be present acorrespondence of the raster of the terminals 27 with the raster of thetest inputs 29.

What is claimed:
 1. Adapter system for a test device (28) for loadedcomponent assembly circuit boards (31), comprising:an adapter part (1')with spring contact pins (2, 3) which are provided for contactingconnection of a respective test point (32, 32') of the loaded componentassembly circuit board (31) with a respective selected test channelcontact (29) of a test channel (a₁, a₂, . . . b₁, . . . c₁, . . .) ofthe test device (28), a raster plate (21, 21') having electrical contactsurfaces (22) arranged on its first outer surface, facing the loadedcomponent assembly circuit board (31), and having test channel terminals(27) for the test channel contacts (29) of the test channels (a₁, a₂, .. . b₁, . . . c₁, . . .) of the test device (28) to be used on a secondouter surface which is oriented opposite to the first outer surface ofthe raster plate (21, 21'), and electrical connections, provided on thesurface or inside the raster plate (21, 21') from electrical contactsurfaces (22) of the first outer surface of the raster plate (21, 21')with respective test channel terminals (27) of the second outer surfaceof the raster plate (21, 21') respectively associated with suchelectrical contact surfaces (22), wherein with reference to the numberof test channel terminals (27) of the test channels (a₁, a₂, . . . b₁, .. . c₁, . . .) of the test device (28) present on the second outersurface, on the first outer surface of the raster plate (21, 21') thenumber of the electrical contact surfaces (22) is multiplied and in eachcase a n-times multiple number of these electrical contact surfaces (22)is respectively has a group (No. 1, No. 2,. . .) electricallyparallel-connected with one another and is connected with a selectivelyassociated test channel to form a group (No. 1, No.
 2. . .), wherein atleast in regions of the first outer surface of the raster plate (21,21') the individual electrical contact surfaces (22) of some of thesegroups (No. 1, No.
 2. . .) and thus of some of the test channels (a₁,a₂, . . . b₁, . . . c₁, . . .) are positioned distributed extensivelymixed amongst one another in such a manner, that an universalapplicability of the raster plate (21, 21') is guaranteed.
 2. Adaptersystem for a test device (28) according to claim 1, characterized inthat,the raster plate (21, 21') is an additional adapter pan (1) to thetest device (28).
 3. Adapter system for a test device (28) according toclaim 1, characterized in that,the raster plate (21, 21') is an integralpart of the test device (28) and a respective n-times multiple number ofthe electrical connect surfaces (22) are direct electrical parallelterminals of a respective one of the test channels (a₁, a₂, . . . b₁, .. . c₁, . . .).
 4. Adapter system for a test device (28) according toclaim 1, characterized in that,electrical connections of the testchannel terminals (27) of the test channel contacts (29) of the testchannels (a₁, a₂, . . . b₁, . . . c₁, . . .) with their respectivelyassociated electrical contact surfaces (22) on the surface or inside theplate (21) are effected as metallisations or conductor paths (131, 141,142, 143).
 5. Adapter system for a test device (28) according to claim1, characterized in that,the raster plate (21) includes metallisations(132, 133) extending over surface areas within a layer construction, asground/potential supply lines.
 6. Adapter system for a test device (28)according to claim 4 or 5, characterized in that,overload protectionelements (150) are included in the connections of the electrical contactsurfaces (22) with the test channel terminals (27).
 7. Adapter systemfor a test device (28) according to claim 1, characterized inthat,electrical contact surfaces (22) with which a number of testchannels (a₁, a₂, . . . b₁, . . . c₁, . . .) is associated whereby thesetest channels (a₁, a₂, . . . b₁, . . . c₁, . . .) are a selection a, bof the available test channels (a₁, a₂, . . . b₁, . . . c₁, . . .) arepositioned distributed mixed amongst one another in a region (A/B) ofthe field of the raster plate (21, 21') and in another region (B/C)electrical contact surfaces (22) of test channels (a₁, a₂, . . . b₁, . .. c₁, . . .) of another selection b, c of the available test channels(a₁, a₂, . . . b₁, . . . c₁, . . .) are positioned distributed mixedamongst one another, so that in both regions (A/B, B/C) electricalcontact surfaces (22) of the selection b are mixed with eitherelectrical contact surfaces (22) of the selection a or of the selectionc.
 8. Adapter system for a test device (28) according to claim 7,characterized in that,electrical contact surfaces (22) of the oneselection a and of the other selection b are arranged mixed with oneanother line-wise.
 9. Adapter system for a test device (28) according toclaim 1, characterized in that,for particularly short connections ofelectrical contact surfaces (22) with the associated test channelterminals (27) of the test channel contacts (29) in/on the raster plate(21, 21') in substance electrical contact surfaces (22) only of a numberof test channels (a₁, a₂, . . . b₁, . . . c₁, . . .) arrangedneighboring one another are arranged distributed mixed with one another.10. Adapter system for a test device (28) according to claim 1,characterized in that,the size of the multiple n of the number ofparallel-connected electrical contact surfaces (22) of each respectivegroup (No.1, No.2, . . . No.21, . . . No.41, . . .) of each test channel(a₁, a₂, . . . b₁, . . . c₁, . . .) is chosen to be of differentmagnitude.
 11. Adapter system for a test device (28) according to claim1, characterized in that,the adapter van (1') includes, for the guidingalso of obliquely set spring contact pins (2, 3), a plurality of guidehole plates (10, 11, 12) arranged parallel spaced apart from oneanother, in which guide hole plates bores (13) for the predeterminedguiding of the spring contact pins (2, 3) placed therein are provided.12. Adapter system for a test device (28) according to claim 1,characterized in that,the adapter part (1') includes a holding plate(112) for the retention of the spring contact pins (102) and at leastone guide hole plate (10, 11) for the guiding of the spring contact pins(102).
 13. Adapter system for a test device (28) according to claim 12,characterized in that,bendable spring contact pins (102) are employed,the bendable portion of which is guided.
 14. After system for a testdevice (28) according to claim 1, characterized in that,in addition tothe normally provided spring contact pins (2, 3, 102), there is provideda spring contact pin pair whose single spring contact pins (202, 203)are connected together by a short wire connection (205).
 15. Adaptersystem for a test device (28) according to claim 1, characterized inthat,there is provided an adapter (1") which contains spring contact pinpairs, the spring contact pins (202', 203') of which that respectivelybelong together being electrically connected with wire connections(205), whereby in each case one spring contact pin (203') of thesespring contact pins (202', 203') is spring-contacted with an electricalcontact surface (22) of the raster plate (21) and the respective otherspring contact pin (202') is spring-contacted with the respective testpoint (32, 32') of the loaded component assembly circuit board (31). 16.Adapter system for a test device (28) according to claim 1,characterized in that,the adapter part (1') in a holding plate (112) inwhich the spring contact pins (302) for spring contacting of the testpoints (32) of the loaded component assembly circuit board (31) are soplaced that the respective spring contact pin (302) forms on the side ofthe holding plate (112) averted from the loaded component assemblycircuit board (31) a contact point (303), and spring contact pins (2, 3)are provided which are guided with the guide hole plates (10, 11, 12).17. Adapter system for a test device (28) according to claim 1,characterized in that,the raster plate (21) is constructed with aplurality of layers with a plurality of planes (17a, 17b, 17c,. . .) andhas through-going bores (1133) and only one or a few bores (1134)extending less deeply, in that in respective planes beneath the lessdeeply extending bores (1134) there are provided respective parallelrunning conductor paths (91, 92) which are directed transversely to oneanother in respective two different planes (17a, 17b, 17c. . .) lyingone above the other and which extend below the less deeply extendingbores (1134) between the through-going bores (1133) and in that thesebores (1133, 1134) each have internal metallisations which aredimensioned suitably for the respective electrical connections, in orderto provide connection contacts between conductor paths of differentplanes (17a, 17b, 17c. . .) and the electrical contact surfaces (22)which are located on the from outer surface of the raster plate (21) andthe contact surfaces of the test channel terminals (27) which arelocated on the second outer surface of the raster plate (21). 18.Adapter system for a test deice (28) according to claim 1, characterizedin that,there is provided a master plate (21') which has as electricalconnections between the electrical contact surfaces (22) of the firstouter surface of the raster plate (21') and the contact surfaces of thetest channel terminals (27) of the second outer surface of the rasterplate (21') in substance wire connections (77), and in that the rasterplate (21') includes two planes (1210, 1211) which are arranged lyingone above the other and of which the one plate (1210) has a field withbores (71) in which pins (73) having electrical contact surfaces (22)are placed and of which the other plate (1211) has a field with bores(72) which are positioned corresponding to the test channel terminals(27), whereby these bores (72) are so dimensioned that wire connections(77) extending from the pins (73) having the electrical contact surfaces(22) can be led in n-times number through each respective bore (72) andcan be connected with the respective test channel terminal (27). 19.Adapter system for a test device (28) according to claim 18,characterized in that,the intermediate space between the two plates(1210, 1211), in which the connection wires (77) run, is filled at leastin part with casting resin in that these two plates (1210, 1211) as aunit form the raster plate (21').
 20. Adapter system for a test device(28) according to claim 1, characterized in that,contact surfaces of thetest channel terminals (27) for the contacting with the test channelcontacts (29) of the test channels (a₁, a₂, . . . b₁, . . . c₁, . . .)of the test device (28) located on the raster plate (21, 21') areelectrically divided at least to some proportion respectively into aplurality of part contact surfaces (27a, 27b. . .), whereby these partcontact surfaces (27a, 27b. . .) are arranged lying near to one anotherand the individual part contact surfaces (27a, 27b. . .) areelectrically connected in each case only with a numerical proportion ofthose electrical connections which connect this test channel terminal(27) with the n-multiple electrical contact surfaces (22) of the firstouter surface of the raster plate (21, 21') associated therewith, whichnumerical proportion corresponds to the division factor, and in that adevice (81) for the selective contacting electrical connection of one ofthese part contact surfaces (27a, 27b. . .) with the test channelcontact (29) of the test device (28) is provided.
 21. Adapter system fora test device (28) according to claim 20, characterized in that,thedevice (81) has the shape of a pin and in that for the individualalignment of the pin there is provided an additional hole plate (82)having correspondingly positioned holes (83).
 22. Adapter system for atest device (28) according to claim 21, characterized in that,for theindividual setting of the pin there is provided an actuator.